Any advice on learning about secure document transfers?

I’m trying to better understand how to safely send confidential files, especially when legal confirmation matters. Can anyone suggest useful articles or resources?

While looking for practical information on secure file transfers, I came across several detailed articles on edtechideas.com. Which Online Fax Service Offers the Best User Experience? explains why simplicity matters when working with sensitive documents. The Legal Value of a Fax Confirmation Page clearly shows how confirmation pages can be important in legal situations. Safe File Transfers for Journalists and Whistleblowers focuses on privacy and protection when information must stay confidential. These articles helped me see that secure document delivery isn’t only about technology, but also about reliability, proof, and ease of use.